Polishing head assembly having recess and cap

Abstract

A polishing head assembly for polishing of semiconductor wafers includes a polishing head and a cap. The polishing head has a top portion and a recess along a bottom portion. The recess has a recessed surface. Holes extend from the top portion through the recessed surface. The cap is positioned within the recess and the cap has an annular wall and a floor extending across the annular wall. The annular wall has apertures corresponding to the holes. The floor is spaced from the recessed surface to form a chamber therebetween. The polishing head assembly also includes a band that circumscribes a portion of the annular wall. The holes and the corresponding apertures receive fasteners to removably secure the annular wall to the recessed surface.

What is claimed is: 
     
         1 . A polishing head assembly for polishing of semiconductor wafers, the polishing head assembly comprising:
 a polishing head having a top portion and a downwardly extending annular member defining a recess along a bottom portion, the recess having a recessed surface, and holes extending from the top portion through the recessed surface;   a cap positioned within the recess, the cap having an annular wall and a floor extending across the annular wall, the floor having a bottom surface and a top surface and being spaced from the recessed surface to form a chamber between the recessed surface and the top surface, wherein the annular wall has apertures corresponding to the holes, and wherein the cap is made of a metallic material; and   a band circumscribing a first portion of the annular wall, wherein the band is made of a non-metallic material;   wherein the annular member circumscribes a second portion of the annular wall;   wherein the thickness of the annular wall in a radial direction is greater at a top portion than at a bottom portion; and   wherein the holes and the corresponding apertures receive fasteners to removably secure the annular wall of the cap to the recessed surface of the polishing head.   
     
     
         2 . The polishing head assembly of  claim 1 , wherein the band is non-unitary having at least two segments. 
     
     
         3 . The polishing head assembly of  claim 2 , wherein the band has an interlocking member to secure the band to the annular wall. 
     
     
         4 . The polishing head assembly of  claim 1 , wherein the band is a unitary one-piece band. 
     
     
         5 . The polishing head assembly of  claim 1 , wherein the band is made of the non-metallic material is selected from the group consisting of polyetherimide, polyether ether ketone, polyphenylene sulfide, and polyethylene terephthalate. 
     
     
         6 . The polishing head assembly of  claim 1 , wherein the annular wall has a top edge that contacts the recessed surface when the annular wall and the recessed surface are secured. 
     
     
         7 . The polishing head assembly of  claim 6 , wherein the top edge comprises an o-ring forming a seal when the annular wall and the recessed surface are secured. 
     
     
         8 . The polishing head assembly of  claim 1 , further comprising a template attached to the bottom surface of the floor, the template comprising a backing film. 
     
     
         9 . The polishing head assembly of  claim 8 , wherein the template is attached to the bottom surface using a pressure sensitive adhesive. 
     
     
         10 . The polishing head assembly of  claim 8 , wherein the template extends outward past an outer surface of the annular wall such that the band overlaps a portion of the template. 
     
     
         11 . The polishing head assembly of  claim 10 , wherein a pressure sensitive adhesive forms a seal at the portion of the template overlapped by the band. 
     
     
         12 . The polishing head assembly of  claim 8 , wherein the template further comprises a retaining ring extending downward from the backing film. 
     
     
         13 . The polishing head assembly of  claim 12 , wherein the retaining ring forms an opening to receive a semiconductor wafer, and wherein a height of the wafer is greater than a height of the retaining ring. 
     
     
         14 . The polishing head assembly of  claim 13 , wherein the template is used with a liquid to retain the wafer on the polishing head assembly by surface tension. 
     
     
         15 . A polishing head assembly for polishing of semiconductor wafers, the polishing head assembly comprising:
 a polishing head having a top portion and a downwardly extending annular member defining a recess along a bottom portion, the recess having a recessed surface, and holes extending from the top portion through the recessed surface;   a cap positioned within the recess, the cap having an annular wall extending between and upper surface and a floor extending across the annular wall, the floor being spaced from the recessed surface to form a chamber therebetween, wherein the annular wall has a first portion and a second portion, the first portion having apertures corresponding to the holes, the second portion extending downward from the first portion, and wherein the cap is made of a metallic material, wherein the thickness of the annular wall adjacent the upper surface is greater than a thickness of the annular wall adjacent the floor; and   a unitary one-piece band circumscribing the second portion of the annular wall, wherein the band is made of a non-metallic material;   wherein the annular member circumscribes a second portion of the annular wall;   wherein the holes and the corresponding apertures receive fasteners to removably secure the first portion of the annular wall of the cap to the recessed surface of the polishing head; and   wherein the first portion of the annular wall has a first o-ring forming a seal when the first portion and the recessed surface are secured.   
     
     
         16 . The polishing head assembly of  claim 15 , wherein the cap has a tab extending outward from the second portion of the annular wall, and a second o-ring forming a seal between the tab and the band. 
     
     
         17 . The polishing head assembly of  claim 15 , wherein the band is made of a non-metallic material selected from the group consisting of polyetherimide, polyether ether ketone, polyphenylene sulfide, and polyethylene terephthalate.